Sending 2 CV outs simultaneously in drum mode

My Hapax recently arrived I and have been having a lot of fun with it. I use it with my modular system and currently don’t own any MIDI gear or interfaces so I’ve been making good use of the CV/Gate outputs.

When using it in Live / drum mode with the ER-301 (using a cv out to index into sample slices and a gate out to trigger them) one thing I struggled with was routing the velocity of the track to an arbitrary CV output without overriding the cv that picked the slices. I’ve looked searched through the manual a bunch without any luck. I wanted to post here to see if I’m missing something and this is of interest before creating a feature request ticket.

For me, this would be a very nice feature to have. Of course, there are some workarounds:

  • Using the Automation section (not perfect and unable to use the drum velocity feature but it kind of works)
  • Buying an FH-1/MIDI to CV converter … I might end up doing this but would rather not since I already have a sequencer in the rack

Is it possible to send velocity and pad values in parallel through CV?
If not, is this something that others would benefit from?

EDIT - Of course, I figured it out right after posting this: you push and twist the encoders of the corresponding pad.

Looks like when I change the value after holding and twisting the corresponding encoder, the main output for the track changes as well. So, my original question remains.

you can’t output Velocity separately

i think you bought the wrong device for your needs… an external Midi/Cv converter will help, but add some latency

an OXI One can do that what you want

i think this is coming in the next firmware update, velocity has been added to the matrix source and destination.

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thats true… but i don’t see how you can define this for each track of the drums-sequencer separately
so thats extremely limited

you right,
thinking about it now i wonder what happens when selecting velocity as a source and simultaneous notes with different velocities are triggered, maybe it keeps the highest value? I will try later.

The average is used


ah makes sense :slight_smile:

@verstaerker since I’m only using one CV/Gate to control the samples/splices, I only need one velocity cv out, as long as the value sent reflects the velocity of the current drum pad being played.

as written here… it outputs all played velocities … so if you’re having other sequences in the drum-seq running those will be output as well

Correct, but I don’t think that should matter if I’m only playing one note at a time anyway, right?

if thats the case it really doesn’t matter … it’s all fine

I can see what you were saying if you wanted to send multiple drum voices in the same track at once. If I want multiple samples at the same time I’d probably just create another drum track.

it’s the whole point of the drum sequencer , to have all drum-voices in one view

of course your workaround would do it

I guess my method of sequencing (using a single CV/Gate to index into different slices) is really the overall limiting factor to playing multiple notes. Sure, I could use some hardware that has 2 cv’s and a gate for each drum voice and then patch them accordingly, but after 2 voices that becomes a little cumbersome and I think I’d prefer to use midi in that context anyway

if you are into diy, the er301 has an i2c interface, you could likely create a small midi i2c bridge to do this task.
it would be cheaper than buying a midi 2 cv module, and would have the advantage of leaving your cv/gate inputs on the er301 free for other uses.

I don’t have a er301, but for percussion I use Rample and a Percussa SSP…
and even though I can drive these via cv (via my Hermod), I just find it much easier/tidier to use midi most of the time, and never really had an issue with latency/jitter… and this leaves the cv inputs for things like modulation, which is where I appreciate cv the most.

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Do you know of any established DIY projects I could follow for this? I’ve actually been chasing this idea for a while and I know there’s a few different projects that have worked toward this goal with varied success, but there’s no clear “MIDI for the ER-301” project/guide at this point.

This Raspberry Pi Zero W project looks the most promising right now.

I’m also aware of the i2c2midi project, but from my understanding this won’t interface with the ER-301 (or at least I haven’t seen any working examples).

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For the record the FH-2 is very low latency, it’s a very good MIDI to CV option for those who own a Haoax and want to squeeze more CV out of it.

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sorry, I don’t have an er301… so no, Im not really actively following it.
I kind of know about this area as I was considering i2c options on the SSP, and so had looked at what had been done with er301/teletype in the i2c area.

from that, id say, id be looking at teensy/arduinos, they have libraries for midi and i2c so its straightforward. pi-w could work, but Im just more familiar with the teensy/ards range.
one thing to mindful of is the master/slave relationship of i2c (I believe er301 is slave?), and also the voltage (i2c can be 5v or 3v3)

with that in mind, i2c2midi… yeah, thats kind of what you need in principle.
however, teletype is master, so needs a slave, whereas (iirc) er301 is a slave, and so needs a master… but depending on chip used this could be a simple matter changing roles.
likely the major change is what i2c ‘messages’ the er301 needs… ie. how do you expose these incoming midi messages to the er301, how does this interface to the er301 modules - that will be very different to the teletype (op-codes), and may need a custom module on the er301 (*)

its a very ‘do-able’ diy project, but not sure there is an off the shelf product, as its a bit niche.

so yeah, I was throwing it out there, on the off chance you were a diy-er, or perhaps there was an active project which you could latch on to.
(otherwise, as others mentioned, there are lots of midi2cv modules at all budget levels)

(*) Ive not looked at how the er301 exposes i2c to modules, as that was a bit detailed for my needs.
but er301 is open enough to allow this to be done… with some coding…